Optical scanner module and method for fabricating optical scanner module

ABSTRACT

The present invention is to provide an optical scanner module. An optical scanner apparatus scans laser light by oscillating a mirror with a piezoelectric element. A package that mounts the optical scanner apparatus and electrically is connected to a substrate via a connector. A package cover that is fixed to the package and seals the optical scanner apparatus so that the optical scanner apparatus is not visually recognized from an outside. The package and the package cover are bonded by a heat curing adhesive agent. A vent for releasing gas in a space where the optical scanner apparatus is sealed is formed in the package cover, and the vent is blocked by ultraviolet curing resin.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application filed under 35U.S.C. 111(a) claiming the benefit under 35 U.S.C. 120 of U.S. patentapplication Ser. No. 15/763,921 filed on Mar. 28, 2018, which is theNational Stage of International Application No. PCT/IB2016/001637, filedon Nov. 18, 2016, which is based on and claims priority to JapanesePriority Application No. 2015-196872 filed on Oct. 2, 2015, the entirecontents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to an optical scanner module and anoptical scanner, control apparatus.

2. Description of the Related Art

Conventionally, an optical scanner module is known in which an opticalscanner apparatus that rotates a mirror around a rotation axis toreflect incident light such as laser light is mounted on a package. Inthis optical scanner module, a displacement sensor that detects anoscillation angle of the mirror under a status that the mirror is drivenand oscillated is provided, inclination of the mirror is detected basedon a signal output from the displacement sensor, and the mirror iscontrolled to be driven (see Patent Document 1, for example).

PATENT DOCUMENT

[Patent Document 1] Japanese Laid-open Patent Publication No.2014-235316

However, a sensor interconnect connected to the displacement sensor anda drive interconnect through which a drive signal for oscillating themirror passes may be drawn in the package in a complicated manner in theabove described optical scanner module. Then, depending on a way ofdrawing the interconnects, cross-talk may be generated between thesensor interconnect and the drive interconnect, and there is a risk thata signal from the sensor interconnect cannot be accurately detected.

SUMMARY OF THE INVENTION

The present invention is made in light of the above problems, andprovides an optical scanner module including an optical scannerapparatus that scans laser light by oscillating a mirror with apiezoelectric element; a package that mounts the optical scannerapparatus and electrically is connected to a substrate via a connector;and a package cover that is fixed to the package and seals the opticalscanner apparatus so that the optical scanner apparatus is not visuallyrecognized from an outside, wherein the package and the package coverare bonded by a heat curing adhesive agent, and wherein a vent forreleasing gas in a space where the optical scanner apparatus is sealedis formed in the package cover, and the vent is blocked by ultravioletcuring resin.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example of an optical scannercontrol apparatus of a first embodiment;

FIG. 2 is a plan view illustrating an example of an optical scannerapparatus constituting the optical scanner control apparatus;

FIG. 3 is a perspective view for describing electric wiring of anoptical scanner module;

FIG. 4 is a view (No. 1) for describing a method of suppressingcross-talk;

FIG. 5A is a view (No. 2) for describing a method of suppressingcross-talk;

FIG. 5B is a view (No. 3) for describing a method of suppressingcross-talk;

FIG. 6 is a view (No. 1) for describing an actual measurement ofcross-talk;

FIG. 7A is a view (No. 2) for describing an actual measurement ofcross-talk;

FIG. 7B is a view (No. 3) for describing an actual measurement ofcross-talk;

FIG. 8 is a perspective view (No. 1) for describing GND strengthening ofa package;

FIG. 9A is a perspective view (No. 2) for describing GND strengtheningof a package;

FIG. 9B is a perspective view (No. 3) for describing GND strengtheningof a package;

FIG. 10A is a view for describing a vent provided at a package cover;and

FIG. 10B is a view for describing the vent provided at the packagecover.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be described herein with reference todrawings. It is to be noted that, in each of the drawings, the samecomponents are given the same reference numerals, and explanations maynot be repeated.

First Embodiment

FIG. 1 is a block diagram illustrating an example of an optical scannercontrol apparatus of a first embodiment. FIG. 2 is a plan viewillustrating an example of an optical scanner apparatus that constitutesthe optical scanner control apparatus.

(Schematic Structure of Optical Scanner Control Apparatus)

First, with reference to FIG. 1 and FIG. 2, a schematic structure of anoptical scanner control apparatus 1 is described. The optical scannercontrol apparatus 1 includes, as main constituents, a circuit unit 10, alight source unit 20, an optical scanner apparatus 30, an optical unit40, a screen 50 and a light quantity detection sensor 60. The opticalscanner control apparatus 1 is, for example, a laser scanning projector.

The circuit unit 10 is a portion that controls the light source unit 20and the optical scanner apparatus 30, and may be constituted by, forexample, a system controller 11, a CPU (Central Processing Unit) 12,various driving circuits such as a buffer circuit 13, a mirror drivingcircuit 14, a laser driving circuit 15 and a temperature control circuit16, and the like.

The light source unit 20 includes an LD module 21, a temperature controlunit 22, a temperature sensor 23 and a beam attenuating filter 24.

The LD module 21 includes lasers 211R, 211G and 211B each of whoseoutput light quantity is changed in accordance with a current value, alight quantity detection sensor 215 that monitors the latest lightquantity of each of the lasers 211R, 211G and 211B, and the like. Thelaser 211R may be a red semiconductor laser and may output light withwavelength λR (640 nm, for example), for example. The laser 211G may bea green semiconductor laser and may output light with wavelength λG (530nm, for example), for example. The laser 211B may be a bluesemiconductor laser and may output light with wavelength λB (445 nm, forexample), for example. As the light quantity detection sensor 215, forexample, a photodiode or the like may be used. The light quantitydetection sensor 215 may be placed at an appropriate position at whichthe light quantity before passing the beam attenuating filter 24 can bedetected.

The temperature control unit 22 may control the lasers 211R, 211G and211B to be predetermined temperatures, respectively. The temperaturesensor 23 may detect temperature of each of the lasers 211R, 211G and211B. As the temperature control unit 22, for example, a Peltier elementmay be used. As the temperature sensor 23, for example, a thermistor maybe used.

The beam attenuating filter 24 is placed at a preceding stage of amirror 310, and light (synthesized light) output from the lasers 211R,211G and 211B is input. The beam attenuating filter 24 has a function toadjust brightness on the screen 50. As the beam attenuating filter 24,an ND (Neutral Density) filter, a liquid crystal device (liquid crystalelement), a polarizing filter or the like may be used. The beamattenuating filter 24 is, for example, inserted to be inclined withrespect to an optical axis of incident light, and light that does notpass (attenuated light) is absorbed or reflected by the beam attenuatingfilter 24.

The optical scanner apparatus 30 is, for example, a MEMS (Micro ElectroMechanical System) that drives the mirror 310 by a piezo-electricelement. The mirror 310 functions as scanning means that forms an imageon the screen 50 by reflecting light (synthesized light) output from thelasers 211R, 211G and 211B, and two-dimensionally scanning the incidentlight in a horizontal direction and in a vertical direction inaccordance with an image signal.

Specifically, as illustrated in FIG. 2, the optical scanner apparatus 30includes the mirror 310, a mirror support portion 320, torsion beams330A and 330B, connecting beams 340A and 340B, driving beams 350A and350B, a movable frame 360, driving beams 370A and 370B and a fixed frame380. The driving beams 350A and 350B respectively include drivingsources 351A and 351B. The driving beams 370A and 370B respectivelyinclude driving sources 371R and 371L. The driving beams 350A and 350Band the driving beams 370A and 370B function as actuators that scanlaser light by oscillating the mirror 310 in upper-lower or left-rightdirections.

The mirror support portion 320 is provided with slits 322 along acircumference of the mirror 310. By providing the slits 322, the mirrorsupport portion 320 can be lightened and stress that is generated whentransmitting torsion by the torsion beams 330A and 330B to the mirror310 can be reduced.

In the optical scanner apparatus 30, the mirror 310 is supported at afront surface of the mirror support portion 320, and the mirror supportportion 320 is connected to end portions of the torsion beams 330A and330B that are provided at both sides of the mirror support portion 320.The torsion beams 330A and 330B form an oscillating axis, and supportsthe mirror support portion 320 from both sides in an axial direction byextending in the axial direction. When the torsion beams 330A and 330Bare distorted, the mirror 310 supported by the mirror support portion320 is oscillated so that reflected light irradiated on the mirror 310is scanned. The torsion beams 330A and 330B are connected to besupported by the connecting beams 340A and 340B, and further connectedto the driving beams 350A and 350B, respectively.

The driving beams 350A and 350B, the connecting beams 340A and 340B, thetorsion beams 330A and 330B, the mirror support portion 320 and themirror 310 are surrounded by the movable frame 360. One side of each ofthe driving beams 350A and 350B is supported by the movable frame 360.The other side of the driving beam 350A extends an inner side to beconnected to the connecting beams 340A and 340B. The other side of thedriving beam 350B similarly extends an inner side to be connected to theconnecting beams 340A and 340B.

The driving beams 350A and 350B are provided as a pair in a directionperpendicular to the torsion beams 330A and 330B such that to interposethe mirror 310 and the mirror support portion 320 therebetween. Thedriving sources 351A and 351B are provided at front surfaces of thedriving beams 350A and 350B, respectively. The driving sources 351A and351B are piezo-electric elements each having a structure in which alower electrode, a piezo-electric film (a PZT film or the like) and anupper electrode are stacked in this order on the surfaces of the drivingbeams 350A and 350B, respectively. Each of the driving sources 351A and351B extends or shrinks in accordance with polar of the drive voltagethat is applied to the upper electrode and the lower electrode.

Thus, by alternately applying drive voltages of different phases to thedriving beam 350A and the driving beam 350B, respectively, the drivingbeam 350A and the driving beam 350B alternately oscillate oppositedirections (upper or lower) at left-right sides of the mirror 310. Withthis, the mirror 310 can be oscillated around an axis while having thetorsion beams 330A and 330B as an oscillating axis or a rotation axis.Hereinafter, a direction in which the mirror 310 is oscillated aroundthe axis of the torsion beams 330A and 330B is referred to as a“horizontal direction”. For example, a resonance frequency is used forhorizontal driving by the driving beams 350A and 350B, and it ispossible to drive the mirror 310 to be oscillated at a high speed.

As such, the driving beams 350A and 350B are horizontal driving beamsincluding horizontal driving sources 351A and 351B that oscillate themirror 310 in the horizontal direction, respectively.

One end of each of the driving beams 370A and 370B is connected to anouter side of the movable frame 360. The driving beams 370A and 370B areconnected to the movable frame 360 at positions that are point symmetrywith respect to the mirror 310 as a center, and are provided as a pairto interpose the movable frame 360 therebetween from left-right sides,respectively. The driving beam 370A includes multiple beams eachextending in parallel with respect to the driving beam 350A whereadjacent beams are connected with each other at respective end portionsto form a zig-zag shape as a whole. The other end of the driving beam370A is connected to an inner side of the fixed frame 380. The drivingbeam 370B includes, similarly, multiple beams each extending in parallelwith respect to the driving beam 350B where adjacent beams are connectedwith each other at respective end portions to form a zig-zag shape as awhole. The other end of the driving beam 370B is connected to an innerside of the fixed frame 380.

The driving sources 371R and 371L are formed on front surfaces of eachof the rectangular beams, not including curbed portions, of the drivingbeams 370A and 370B, respectively. The driving sources 371R and 371L arepiezo-electric elements each having a structure in which a lowerelectrode, a piezo-electric film and an upper electrode are stacked inthis order on the surfaces of the driving beams 370A and 370B,respectively.

In the driving beams 370A and 370B, by applying driving voltages ofdifferent polarities to the adjacent driving sources 371R and 371L ofthe adjacent rectangular beams, the adjacent rectangular beams arewarped in the opposite directions in the upper and lower direction.Thus, the accumulated movement of the rectangular beams in the upper andlower direction is transmitted to the movable frame 360. The drivingbeams 370A and 370B oscillate the mirror 310 in the vertical direction,which is perpendicular to the horizontal direction by this operation.For example, for the vertical driving by the driving beams 370A and370B, a non-resonance frequency may be used.

For example, the driving source 371R includes driving sources 371AR,371BR, 371CR, 371DR, 371ER and 371FR that are aligned rightward from amovable frame 360 side. The driving source 371L includes driving sources371AL, 371BL, 371CL, 371DL, 371EL and 371FL that are aligned leftwardfrom a movable frame 360 side. In such a case, by driving the drivingsources 371AR, 371BL, 371CR, 371DL, 371ER and 371FL by the samewaveform, and the driving sources 371BR, 371AL, 371DR, 371CL, 371FR and371EL by the waveform with different phase from that for the drivingsources 371AR, 371BL, 371CR, 371DL, 371ER and 371FL, the mirror 310 canbe oscillated in the vertical direction.

As such, the driving beams 370A and 370B are vertical driving beamsincluding vertical driving sources 371R and 371L that oscillate themirror 310 in the vertical direction, respectively.

Drive interconnects that apply drive voltage to the upper electrode andthe lower electrode of the driving source 351A are connected topredetermined terminals of a group of terminals TA provided at the fixedframe 380. Drive interconnects that apply drive voltage to the upperelectrode and the lower electrode of the driving source 351B areconnected to predetermined terminals of a group of terminals TB providedat the fixed frame 380. Drive interconnects that apply drive voltage tothe upper electrode and the lower electrode of the driving source 371Rare connected to predetermined terminals of the group of terminals TAprovided at the fixed frame 380. Drive interconnects that apply drivevoltage to the upper electrode and the lower electrode of the drivingsource 371L are connected to predetermined terminals of the group ofterminals TB provided at the fixed frame 380.

The optical scanner apparatus 30 includes a horizontal displacementsensor 391 that detects inclination (oscillation angle in the horizontaldirection) of the mirror 310 in the horizontal direction when the drivevoltage is applied to the driving sources 351A and 351B and the mirror310 is oscillated in the horizontal direction. Numerals “392”, “393” and“394” are dummy sensors.

The optical scanner apparatus 30 includes vertical displacement sensors395 and 396 that detect inclination (oscillation angle in the verticaldirection) of the mirror 310 in the vertical direction when the voltageis applied to the driving sources 371R and 371L and the mirror 310 isoscillated in the vertical direction.

Referring back to FIG. 1, the optical unit 40 is an optical system thatprojects light scanned by the optical scanner apparatus 30 on the screen50. The light input in the optical unit 40 from the optical scannerapparatus 30 forms an image on the screen 50, and an image correspondingto the image signal is displayed on the screen 50.

The screen 50 includes, for example, a micro-lens array for removingnoises of an image that are seen as particles called speckles. In such acase, each of the micro-lenses that compose the micro-lens arraycorresponds to a pixel of a display, and it is preferable that anirradiated laser beam is equal to a size of the micro-lens or less thanthe size of the micro-lens.

The light quantity detection sensor 60 may be placed at an appropriateposition at which the quantity of the light that passes the beamattenuating filter 24 can be detected. The light quantity detectionsensor 60 is capable of independently detecting the light quantity ofeach of the lasers 211R, 211G and 211B after passing the beamattenuating filter 24. As the light quantity detection sensor 60, forexample, one or a plurality of photodiodes or the like may be used.

(Schematic Operation of Optical Scanner Control Apparatus)

Next, an operation of the optical scanner control apparatus 1 isschematically described. The system controller 11, that is a controlunit, generates a drive signal based on a signal obtained via the sensorinterconnect, for example. The mirror driving circuit 14 drives themirror 310 based on the drive signal generated by the system controller11, for example.

More specifically, the system controller 11 may control an oscillatingangle of the mirror 310, for example. The system controller 11 maymonitor inclination of the mirror 310 in the horizontal direction andthe vertical direction obtained at the horizontal displacement sensor391 and the vertical displacement sensors 395 and 396 via a buffercircuit 13, and supply an angle control signal to a mirror drivingcircuit 14, for example. Then, the mirror driving circuit 14 may supplypredetermined drive signals to the driving beams 351 and 352 and thedriving beams 371 and 372 based on the angle control signal from thesystem controller 11 to drive (scan) the mirror 310 at a predeterminedangle.

Further, the system controller 11 may supply, for example, a digitalimage signal to a laser driving circuit 15. Then, the laser drivingcircuit 15 may supplies predetermined current to the lasers 211R, 211Gand 211B based on the image signal from the system controller 11. Withthis, the lasers 211R, 211G and 211B emit lights of red, green and bluethat are modulated in accordance with the image signal, respectively,and by synthesizing these lights, a color image can be formed.

The CPU 12 may monitor primitive light quantity output from each of thelasers 211R, 211G and 211B by the output of the light quantity detectionsensor 215, and supply a light quantity control signal to the LD module21, for example. Each of the lasers 211R, 211G and 211B is currentcontrolled to output predetermined light quantity based on the lightquantity control signal from the CPU 12.

Here, the light quantity detection sensor 215 may include three sensorseach independently detecting the light quantity of the each of thelights output from the lasers 211R, 211G and 211B. Alternatively, thelight quantity detection sensor 215 may be constituted by a singlesensor. In such a case, it is possible to control the light quantity ofthe light out from each of the lasers 211R, 211G and 211B by causing thelasers 211R, 211G and 211B to emit light in order, and detecting by thesingle sensor.

Further, the CPU 12 may monitor temperatures of the lasers 211R, 211Gand 211B by monitoring the output of the temperature sensor 23, andsupply a temperature control signal to a temperature control circuit 16.Then, the temperature control circuit 16 supplies predetermined currentto the temperature control unit 22 based on the temperature controlsignal from the CPU 12. With this, the temperature control unit 22 isheated or cooled, and each of the lasers is controlled to bepredetermined temperature.

The light quantity detection sensor 60 detects light quantity of lightafter passing through the beam attenuating filter 24. As describedabove, the light quantity detection sensor 215 for adjusting the lightquantity of each of the lasers is mounted in the LD module 21, and thelight quantity detection sensor 215 detects primitive output lightquantity of each of the lasers 211R, 211G and 211B (before passingthrough the beam attenuating filter 24). However, as an image that isactually displayed in the optical scanner control apparatus 1 is formedby light imaged on the screen 50, there may be a case that the light isnot appropriately adjusted by an adjustment based on the primitive laserlight quantity.

For example, as the beam attenuating filter 24 is provided on an opticalpath, depending on characteristics of the beam attenuating filter 24,there may be a case that an expected attenuating ratio cannot beobtained, and the light quantity after passing the beam attenuatingfilter 24 does not become an expected value. Further, when attenuatingratios of R/G/B of the beam attenuating filter 24 are dispersed, balanceafter passing through the beam attenuating filter 24 may not beretained. Further, there may be a case that characteristics of theoptical scanner apparatus 30 are changed due to temperature or ageddeterioration. Such problems cannot be dissolved even if the lightquantity before passing through the optical scanner apparatus 30 isprecisely controlled by the light quantity detection sensor 215.

Thus, in the optical scanner control apparatus 1, as light quantitydetection means for detecting the light quantity after passing throughthe beam attenuating filter 24, a light quantity detection sensor 60, isprovided. A detection result of the light quantity detection sensor 60is input in the CPU 12, and the CPU 12 may supply a light quantitycontrol signal for controlling a current value of each of the lasers tothe LD module 21 based on the light quantity detected by the lightquantity detection sensor 60.

With this, light quantity of the laser light including variation of thecharacteristics of the beam attenuating filter 24 can be detected. Thus,the light quantity can be accurately controlled so as to correspond toan image that is actually displayed on the screen 50. Here, the lightquantity detection sensor 60 may independently detect the light quantityof each of the lasers 211R, 211G and 211B, and the CPU 12 may controlthe current value of each of the lasers based on the respective lightquantity detected by the light quantity detection sensor 60.

(Electric Wiring of Optical Scanner Module)

FIG. 3 is a perspective view for describing electric wiring of theoptical scanner module. As illustrated in FIG. 3, the optical scannermodule 400 includes the optical scanner apparatus 30, a package 410, aconnector 450 and a substrate 490. As will be described later, theoptical scanner module 400 may include a package cover 420, a coverglass 430 and the like (see FIG. 8 and the like).

In the optical scanner module 400, the optical scanner apparatus 30 ismounted on the package 410, and the package 410 is connected to thesubstrate 490 via the connector 450. The package 410 is, for example, aceramic package, and stacked interconnects (10 layers of interconnects,for example) are provided in the package 410. Here, the package 410 maybe a printed wiring board and the like, other than the ceramic, and abase material is not limited as long as it is possible to form amultilayer interconnection board (substrate).

The substrate 490 is, for example, a flexible printed wiring board. Asensor interconnect P_(S), a drive interconnect P_(D) and a GNDinterconnect P_(G), which will be described later, are drawn from theoptical scanner apparatus 30 into the package 410, and further drawn inthe substrate 490.

As described above, when controlling an oscillating angle of the mirror310, the system controller 11 uses sensor signals obtained by thehorizontal displacement sensor 391 and the vertical displacement sensors395 and 396. Further, these sensor signals are used for controllingtiming for emitting laser and ringing, detecting failures and the like,in addition to controlling the oscillating angle. It is important toaccurately detect the sensor signals of the horizontal displacementsensor 391 and the vertical displacement sensors 395 and 396 in order tocontrol them.

Sensor signals of the horizontal displacement sensor 391 and thevertical displacement sensors 395 and 396 are connected from the groupof terminals TA and TB of the optical scanner apparatus 30 to a group ofterminals TC and TD of the package 410. Then, the sensor signals passthrough the stacked interconnects in the package 410, and further passthrough the connector 450 and interconnects of the substrate 490 toreach a group of terminals TE. Further, similarly as the sensor signals,a horizontal driving signal and a vertical drive signal for driving themirror 310 are connected from the group of terminals TA and TB of theoptical scanner apparatus 30 to the group of terminals TE.

If an electrical cross-talk between interconnects occurs in theinterconnects from the optical scanner apparatus 30 to the group ofterminals TE, the sensor signals cannot be accurately detected. Inparticular, if cross-talk occurs between the horizontal driving signaland the horizontal displacement sensor 391, and between the verticaldrive signal and the vertical displacement sensors 395 and 396, anoriginal sensor output and a signal output due to the cross-talk aredetected at the same time with the same waveform and the same frequency,from a sensor output.

Thus, even if the mirror 310 fails, and does not oscillate, as long asthe interconnect is electrically connected, there is a rick that adefect will be generated, such as a sensor output is detected. Inparticular, as a plurality of interconnects are three-dimensionallyprovided in the package 410 including the stacked interconnects, and anelectrical cross-talk is easily generated, a countermeasure to preventgeneration of an electrical cross-talk is necessary.

The above described electrical cross-talk strongly depends on mutualcapacitance and mutual inductance between interconnects.

A cross-talk by mutual capacitance is a phenomenon in which adjacentinterconnects become a capacitor when having capacitance, and if one ofthe interconnects is electrically charged, electrical charge is inducedeven through lines are directly connected, and the other of theinterconnects is also electrically charged. In such a case, themagnitude of the cross-talk is determined by the mutual capacitance andinput voltage applied to the interconnects. Thus, according to theembodiment, in order to suppress (reduce) the cross-talk by the mutualcapacitance, the following countermeasure is taken for the stackedinterconnects of the package 410.

Specifically, as illustrated in FIG. 4, in each layer of the stackedinterconnects, a GND interconnect P_(G) is provided to be sandwichedbetween an interconnect P_(S) and an interconnect P_(D). Further, a GNDsurface (GND layer) are provided around the interconnect P_(S) and theinterconnect P_(D). With this, capacitance is hardly formed between theinterconnect P_(S) and the interconnect P_(D). Here, in FIG. 4, theinterconnect P_(S) is a sensor interconnect that is connected to thedisplacement sensor, and the interconnect P_(D) is a drive interconnectthrough which a drive signal for oscillating the mirror 310 passes (thesame in the following).

Further, in each layer of the stacked interconnects, it is preferablethat a GND layer LG including a GND surface whose entire surface isgrounded is sandwiched between interconnect layers L1 and L2 in each ofwhich the interconnect P_(S) and the interconnect P_(D) are formed. Thismeans that it is preferable that a GND is sandwiched betweeninterconnects in the vertical direction not only in a planar directionof the interconnects. With this, each of the interconnect P_(S) and theinterconnect P_(D) is surrounded by the GND interconnect P_(G) providedbetween the interconnects and the GND surface provided at the lower GNDlayer LG, and capacitance is hardly generated. Although the it isexemplified that the entire surface of the GND layer LG is formed as aGND layer, the GND interconnect P_(G) may be provided right below eachof the interconnects of the interconnect layers L1 and L2 along each ofthe interconnects P_(S) and P_(D). This means that the GND interconnectP_(G) may be linearly provided, not as a plane.

A cross-talk by mutual inductance is a phenomenon in which a magneticfield is generated by electromagnetic induction when a current flowingthrough each of the interconnects varies in accordance with time, and anelectromotive force is generated by the magnetic field.

In such a case, the magnitude of the cross-talk is determined byvariability of current with time and an amount of the current. Thus,according to the embodiment, in order to suppress (reduce) thecross-talk by the mutual inductance, the following countermeasure istaken for the stacked interconnects of the package 410.

Specifically, as illustrated in a plan view of FIG. 5A, in each layer ofthe stacked interconnects, the interconnect P_(S) provided at a certainlayer and the interconnect P_(D) provided at a layer that is adjacent tothe interconnect P_(S) at an upper side or a lower side are provided notto overlap in a plan view. A distance L when the interconnect P_(S) andthe interconnect P_(D) are seen in a plan view, is at least greater thanor equal to a width of an interconnect (greater than or equal to 0.05mm, for example), and it is preferable that the distance L is as largeas possible.

Here, the interconnect P_(S) provided at the certain layer and theinterconnect P_(D) provided at the layer that is adjacent to theinterconnect P_(S) at the upper side or the lower side may be providedsuch that portions extending in substantially the same direction are notoverlapped in a plan view. However, the interconnect P_(S) and theinterconnect P_(D) may have portions that are partially overlapping witheach other in a plan view. FIG. 5B illustrates such an example. Theinterconnect P_(S) and the interconnect P_(D) illustrated in FIG. 5B areprovided such that portions extending substantially in the samedirection (portions laterally extending in the drawing) are notoverlapped with each other in a plan view. However, the interconnectsinclude portions that are crossing in a plan view.

As such, as illustrated by a plan view of FIG. 5B, when theinterconnects (the interconnect P_(S) and the interconnect P_(D)) arecrossing with each other, it is preferable that a crossing angle is notan acute angle and the interconnects are crossing in a perpendiculardirection as much as possible. This is to reduce generation ofelectromotive force by electromagnetic induction. Further, when theinterconnect P_(S) and the interconnect P_(D) are provided in the samelayer, it is preferable that the interconnect P_(S) and the interconnectP_(D) are not in parallel. Further, even when the interconnect P_(S) andthe interconnect P_(D) are provided in different layers, it ispreferable that the interconnect P_(S) and the interconnect P_(D) arenot in parallel.

Although the stacked interconnects of the package 410 are described withreference to FIG. 4, FIG. 5A and FIG. 5B, it is preferable that the samecounter measures are taken for the interconnects of the substrate 490.This is to furthermore reduce the cross-talk.

(Study on Cross-Talk)

Next, suppression of the cross-talk described above with reference toFIG. 3 to FIG. 5B was studied. Here, the horizontal sensor signal isreferred to as “H_SENS”, the vertical sensor signal is referred to as“V_SENS” the horizontal driving signal is referred to as “H_DRV” and thevertical drive signal is referred to as “V_DRV”.

Specifically, simulations of the mutual capacitance and the mutualinductance between H_DRV and H_SENS, between H_DRV and V_SENS, betweenV_DRV and H_SENS, and between V_DRV and V_SENS were conducted. Resultsare illustrated in Table 1 and Table 2.

Here, interconnects are designed in consideration of FIG. 4, FIG. 5A andFIG. 5B in the package 410, but interconnects are not designed inconsideration of FIG. 4, FIG. 5A and FIG. 5B in a conventional package(this is the same in the following). This means that a GND is notprovided between interconnects in each layer, or between layers in thevertical direction, and a portion at which interconnects in the verticaldirection are overlapped or a portion at which the interconnects in thevertical direction are crossing in an acute angle are included, in theconventional package.

TABLE 1 MUTUAL CAPACITANCE SIMULATION VALUE CONVENTIONAL PACKAGE PACKAGE400 UNIT [pF] H_DRV V_DRV H_DRV V_DRV H_SENS 1.31 7.72 0.07 0.02 V_SENS0.47 9.17 0.01 0.13

TABLE 2 MUTUAL INDUCTANCE SIMULATION VALUE CONVENTIONAL PACKAGE PACKAGE400 UNIT [nH] H_DRV V_DRV H_DRV V_DRV H_SENS 0.80 0.90 0.78 0.74 V_SENS0.85 1.07 0.71 0.87

As illustrated in Table 1 and Table 2, it can be understood that themutual capacitance and the mutual inductance are reduced in the package410 compared with the conventional package. In particular, the mutualcapacitance is largely reduced.

Next, under a status that the optical scanner apparatus 30 was notmounted on the package 410 as illustrated in FIG. 6, cross-talk to theH_SENS when applying predetermined voltage on the H_DRV, and cross-talkto the V_SENS when applying predetermined voltage on the V_DRV wereactually measured. Results are illustrated in Table 3.

TABLE 3 CROSS-TALK VOLTAGE MEASURE- CONVEN- APPLIED MENT TIONAL PACKAGEIMPROVED TERMINAL TERMINAL PACKAGE 400 EFFECT H_DRV H_SENS 80 mV 20 mV−75% V_DRV V_SENS 1,200 mV 200 mV −84%

As illustrated in Table 3, it was confirmed that the cross-talk wasimproved for 75% at the horizontal side and 84% at the vertical in thepackage 410 compared with the conventional package.

Next, under a status that the optical scanner apparatus 30 was mountedon the package 410 as illustrated in FIG. 3, cross-talk to the H_SENSwhen applying predetermined voltage on the H_DRV, and cross-talk to theV_SENS when applying predetermined voltage on the V_DRV were actuallymeasured. Results are illustrated in FIG. 7A and FIG. 7B. FIG. 7Aillustrates the results of the conventional package, and FIG. 7Billustrates the results of the package 410.

As illustrated in FIG. 7A, the waveform of the V_SENS is the same as thewaveform of the V_DRV in the conventional package. According to thestructure of the optical scanner apparatus 30, originally, phases of thewaveform of the V_SENS and the waveform of the V_DRV should be reversed180 degrees, however, as the cross-talk from the V_DRV to the V_SENS islarge, they became the same phase.

On the other hand, as illustrated in FIG. 7B, it can be understood thatphases of the waveform of the V_SENS and the waveform of the V_DRVpackage 410 were reversed 180 degrees in accordance with a theory, andan original sensor waveform that reflected a driving status of themirror 310 was output to the caV_SENS.

As such, in the optical scanner module 400, when the sensor interconnectand the drive interconnect are stacked, the sensor interconnect and thedrive interconnect are placed not to overlap with each other in a planview. Further, when the sensor interconnect and the drive interconnectare formed in a same layer, a GND interconnect is provided between theadjacent sensor interconnect and the drive interconnect. With thisconfiguration, cross-talk generated between the sensor interconnect andthe drive interconnect can be reduced, and a signal from the sensorinterconnect can be accurately detected.

Further, in the optical scanner module 400, when the sensor interconnectand the drive interconnect are stacked, it is preferable that a GNDinterconnect is provided between the sensor interconnect and the driveinterconnect that are adjacent in the upper and lower direction.Further, when the sensor interconnect and the drive interconnect thatare adjacent in the upper and lower direction are crossing with eachother, it is preferable that they are placed such that toperpendicularly cross with each other. With this configuration,cross-talk generated between the sensor interconnect and the driveinterconnect can be furthermore reduced, and a signal from the sensorinterconnect can be furthermore accurately detected.

Second Embodiment

In a second embodiment, an example in which the GND is strengthened isdescribed. Here, the same components that are already described in theabove embodiment may not be repeated.

FIG. 8 is a perspective view (No. 1) for describing strengthening theGND of the package. As illustrated in FIG. 8, the package cover 420 isprovided on the package 410 so as to cover the optical scanner apparatus30 in the optical scanner module 400. Here, as the optical scannerapparatus 30 is covered by the package cover 420, the optical scannerapparatus 30 cannot be seen in FIG. 8.

An opening is provided at a substantially center portion of the packagecover 420 that exposes a vicinity of the mirror 310 of the opticalscanner apparatus 30, and the cover glass 430 that transmits incidentlight and output light is provided so as to cover the opening.

Further, GND interconnects P_(G) are provided at an outer edge portionof a surface of the package 410 at which the optical scanner apparatus30 is mounted and at a position that is exposed from the package cover420 to be externally connected. Each of the GND interconnects P_(G) isdrawn from the GND interconnect in the package 410 to the surface of thepackage 410. The number of the GND interconnect P_(G) may be one orplural. As an example, the GND interconnect P_(G) is provided at each offour corners of the surface of the package 410 at which the opticalscanner apparatus 30 is mounted.

FIG. 9A and FIG. 9B are perspective views (No. 2) for describingstrengthening the GND of the package. As illustrated in FIG. 9A, thepackage 410 is fixed to a housing 600 while facing a GND interconnectP_(G) side to the housing 600 by hold pins 700 (fixing member). Thepackage cover 420 including the cover glass 430 is exposed at anopposite surface of the housing 600 from an opening provided in thehousing 600, and light can be input into and output from the opticalscanner apparatus 30.

FIG. 9B illustrates a status in which the package 410 is attached to thehousing 600 (not illustrated in FIG. 9B). As illustrated in FIG. 9B,each of the hold pins 700 has a structure in which a cylindrical portionwith a small diameter is substantially concentrically provided at afront end of a cylindrical portion with a large diameter.

While pressing and contacting the package 410 to the housing 600, a sidesurface of the cylindrical portion with a large diameter of each of thehold pins 700 is contacted at a groove 410 x having a substantially Vshape provided at a side surface of the package 410, and the cylindricalportion with a small diameter is inserted in a hole provided in thehousing 600 to fix the respective hold pin 700. At this time, by formingthe hole to be larger, and laterally moving the hold pin 700, a positionof the package 410 with respect to the housing 600 can be adjusted (inother words, a position of the mirror 310 can be adjusted).

The housing 600 is made of a metal or an insulating body whose surfaceis coated by a metal, and is grounded. When attaching the package 410 tothe housing 600, the GND interconnect P_(G) and the surface of thehousing 600 are physically contacted, and both (both GNDs) areelectrically connected. As the housing 600 is a stable GND, the GNDinterconnect P_(G) and the GND in the package 400 connected to the GNDinterconnect P_(G) are strengthened. Thus, by strengthening the GND asdescribed in the second embodiment, in addition to the method ofsuppressing the cross-talk by the mutual capacitance described in thefirst embodiment, the cross-talk by the mutual capacitance can befurthermore suppressed.

As illustrated in FIG. 10A, a vent 420 x is provided in the packagecover 420, and ultraviolet curing resin or the like is filled in thevent 420 x to block the vent 420 x. FIG. 10B illustrates the vent 420 xin an enlarged manner before the vent 420 x is filled with theultraviolet curing resin or the like. The reason for providing the vent420 x is as follows.

The structure of FIG. 10A may be manufactured by, for example, afterbonding the cover glass 430 to the package cover 420, curing the packagecover 420 including the cover glass 430 to the package 410 by a heatcuring adhesive agent.

However, when curing the heat curing adhesive agent, gas in a sealedspace sealed by the package cover 420 including the cover glass 430 andthe package 410 may expand and the adhesive agent may be cured while thepackage cover 420 is floated.

If the adhesive agent is cured while the package cover 420 is floated,the sealed space cannot be sealed and dusts in air enter the sealedspace. At this time, as the mirror 310 is driven at high-speed, thedusts in air may collide against a surface of the mirror 310 and themirror 310 may be contaminated. In order to prevent such contamination,it is necessary to seal with clean gas.

Thus, the vent 420 x is provided at the package cover 420. With thisconfiguration, when curing the heat curing adhesive agent, the expandedgas in the sealed space can be released from the vent 420 x. Then, afterthe heat curing adhesive agent is cured, by blocking the vent 420 x byultraviolet curing resin or the like at ambient temperature again, thesealed space can be surely sealed without the package cover 420 beingfloated.

Although preferred embodiments have been specifically illustrated anddescribed, it is to be understood that minor modifications may be madetherein without departing from the spirit and scope of the invention asdefined by the claims.

For example, an example is described in the above embodiments in whichthe optical scanner control apparatus of the invention is applied to thelaser scanning projector. However, this is just an example, and theoptical scanner control apparatus of the invention may be applied tovarious devices for displaying an image on a screen. For such devices,for example, an on-vehicle head up display, a head mount display, alaser printer, a laser scanning epilator, a laser head lamp, a laserradar or the like may be exemplified.

-   10 circuit unit-   11 system controller-   12 CPU-   13 buffer circuit-   14 mirror driving circuit-   15 laser driving circuit-   16 temperature control circuit-   20 light source unit-   21 LD module-   22 temperature control unit-   23 temperature sensor-   24 beam attenuating filter-   30 optical scanner apparatus-   40 optical unit-   50 screen-   60 light quantity detection sensor-   211R, 211G, 211B laser-   215 light quantity detection sensor-   310 mirror-   320 mirror support portion-   322 slit-   330A, 330B torsion beam-   340A, 340B connecting beam-   350A, 350B, 370A, 370B driving beam-   351A, 351B, 371R, 371L driving source-   360 movable frame-   380 fixed frame-   391 horizontal displacement sensor-   392, 393, 394 dummy sensor-   395, 396 vertical displacement sensor-   400 optical scanner module-   410 package-   410 x groove-   420 package cover-   420 x vent-   430 cover glass-   450 connector-   490 substrate-   600 housing-   700 hold pin

What is claimed is:
 1. An optical scanner module, comprising: an opticalscanner apparatus that scans laser light by oscillating a mirror with apiezoelectric element; a package that mounts the optical scannerapparatus and electrically is connected to a substrate via a connectorwherein the package has a first side surface and a second side surface;the first side surface has a first V-shaped groove; the second sidesurface has a second V-shaped groove; and the first groove contacts afirst hold pin and the second groove contacts a second hold pin to fixthe package to a housing; and a package cover that includes a coverglass, and is fixed to the package and seals the optical scannerapparatus so that the optical scanner apparatus is at least partiallyviewable directly or from certain angles from an outside, wherein thepackage and the package cover are bonded by a heat curing adhesiveagent, and wherein a vent for releasing gas in a space where the opticalscanner apparatus is sealed is formed in the package cover to penetratethrough the surface of the package cover, and the vent is blocked byultraviolet curing resin.
 2. A method for fabricating an optical scannermodule, which includes an optical scanner apparatus that scans laserlight by oscillating a mirror with a piezoelectric element, a packagethat mounts the optical scanner apparatus and electrically is connectedto a substrate via a connector wherein the package has a first sidesurface and a second side surface; the first side surface has a firstV-shaped groove; the second side surface has a second V-shaped groove;and the first groove contacts a first hold pin and the second groovecontacts a second hold pin to fix the package to a housing, and apackage cover that includes a cover glass, and is fixed to the packageand seals the optical scanner apparatus so that the optical scannerapparatus is at least partially viewable directly or from certain anglesfrom an outside, the method comprising: applying a heat curing adhesiveagent for bonding the package and the package cover; releasing, from avent provided in the package cover to penetrate through a surface of thepackage cover, gas expand in a space formed by the package cover and thepackage when curing the heat curing adhesive agent; and sealing the ventby filling ultraviolet curing resin in the vent and curing theultraviolet curing resin after the heat curing adhesive agent has cured.